The final remains of Dolly (the world's first cloned sheep) at the Royal Museum of Scotland, Edinburgh. Photograph: Murdo Macleod

"Playing God since 1660" reads the motto on the Royal Society's sign in a scene from The Pirates! In an Adventure with Scientists, the latest film from the makers of Wallace and Gromit. And now I can no longer enter the doors of our national science academy without quoting the Pirate Captain's rallying cry, "Prepare to be boarded, nerds!".

Earlier this year I presented a BBC2 Horizon programme on synthetic biology. Our choice of title, Playing God, was not intended as a criticism of synthetic biologists, but rather to highlight an allegation they often face. Environmentalists, religious figures and sections of the media regularly use the phrase as a handy stick with which to beat those in the field. Scientists, they claim, are foolishly meddling in matters that should be left to the gods or nature.

Synthetic biology means different things to different people. Its leading scientists want to create, characterise and, crucially, standardise individual pieces of DNA. The purpose is to build biological circuits with specific functions, in much the same way that you might arrange components to make an electrical circuit. Others want to produce new versions of genetic code with entirely new letters and entirely unnatural versions of DNA.

The ability to design and build biological systems provides a new way to understand how living things work, yet the field is much more about engineering than it is about pure science. However, many synthetic biologists are seeking to solve problems in more efficient ways than traditional engineering does, with potential applications ranging from fighting pollution and cancer to manufacturing fuel and drugs.

Researchers in California, for example, have created synthetic circuits for yeast cells that produce a chemical called artemisinin, a key anti-malarial drug. This will be cheaper than getting it from the plant Artemisia annua, the current production method.

Nasa is investigating ways to create bacteria that counter the effects of radiation sickness in astronauts. Meanwhile, a US–Swiss group has engineered a genetic circuit designed to detect and destroy cancer cells without inflicting the unintended damage caused by chemotherapy and radiotherapy.

Prometheus, a titan in Greek mythology, stole fire from the gods and gave it to humans. His punishment was to be bound to a rock, have his liver plucked out by an eagle and regrown overnight, so that his ordeal could be played out repeatedly. The idea – and the negative connotations – of humans acquiring god-like powers is culturally embedded in legends such as this.

Yet there is almost no aspect of human behaviour that isn't some form of manipulation of the environment for our own purposes. Farming, which we've been doing for more than 10,000 years, is quite the opposite of natural. Breeding, known scientifically as "artificial selection", is the process of mixing genes by design to engineer cheap and plentiful food.

Detractors use the phrase "playing God" to provoke emotive opposition without defining what it is about synthetic biology that is qualitatively different to the previous advances that they enjoy and benefit from every day. Should we go back to the time before humans started playing God through their development of sanitation, vaccines and measures to counter widespread child mortality?

There will be very few aspects of our lives that will remain untouched by synthetic biology. Advancing technology is not risk-free, and needs to be regulated, understood and, if necessary, curtailed. But those decisions need to be made as part of informed public conversations about the relative risks and benefits. The opportunities are too great for synthetic biology to be written off with fear-mongering maxims.

If playing God involves developing technologies that cure diseases, clean up pollution and create new forms of fuel, then these potential benefits need to be considered without the burden of vague, simplistic soundbites.

Only with engaged and rational public discussions about what a technology such as synthetic biology means, and what it can and can't achieve, can we harness it to create a better future.

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